Yellowfin tuna are being caught far north of their typical range this season. Photo by Mark Rayor

A developing El Niño in the equatorial Pacific has generated the usual predictions of drastic weather changes—some devastating, some beneficial—throughout the world.

There’s a 90 percent probability that an El Niño will form, according to some experts. That’s up considerably from previous predictions, but the main question at this point is whether this will be moderate El Niño or, more likely, a powerful warm-water event such as those in the early 1980s and late ’90s.

(El Niño is characterized by unusually warm sea-surface temperatures in the equatorial Pacific, whereas a La Niña is characterized by unusually cold temperatures. Strong El Niños typically alter weather patterns and can cause severe flooding in some areas, and droughts in others.)

The extent of El Niño’s strength won’t be known until late summer or fall. But based on several interesting signals, in the form of mammals, birds, and fish showing up where they don’t typically belong, it’s looking as though this El Niño is going to be a very powerful event.

Earlier this week two Bryde’s whales, a mother and calf, were photographed during two voyages on the same day off Huntington Beach, California, by researcher Alisa Schulman-Janiger.

Bryde’s whales, which measure to about 45 feet, are fairly common in Mexico’s Sea of Cortez. Sightings off California, however, are extremely rare.

Schulman-Janiger said that during NOAA surveys off California between 1991 and 2005, there was only one confirmed sighting of Bryde’s whales, which are also referred to as “tropical whales” because they prefer a warm environment.

Less than a week earlier, a large pod of pilot whales showed off Dana Point on the Orange County coast. Pilot whales are found around the world, including off Mexico, but it had been nearly 20 years since they were last spotted off Southern California.

Fishermen are seeing signs, also. Anglers out of San Diego, on short excursions into Mexican waters, began catching yellowfin tuna in May. That’s unprecedented, according to some, as this sub-tropical species typically doesn’t show that far north until late summer, if at all.

During the El Niño in 1983 to 1984 and 1997 to 1998, however, yellowfin tuna migrated north early and, during the summer, were caught well into U.S. waters. (The 1997-98 El Niño generated heavy rainfall throughout California during the winter, and prolonged periods of rough seas exacted a heavy toll on sea lions and other mammals. Sub-tropical fish species were biting as far north as Oregon.)

“We’ve already started to see very unusual fish catches here,” Tim Barnett, marine research emeritus with the San Diego-based Scripps Institution of Oceanography, told KPBS. “The first yellowfin tuna was caught in May—that has never happened before to anybody’s recollection.

“And the other thing too is the first dorado (mahi-mahi)—first of June. That has never happened before. They really like the warm water and you normally don’t see them here until September.”

Barnett said the 1997 to 1998 El Niño, the biggest in a century, caused a northward shift of the entire fishery population, and he predicts a similar event is developing.

Water temperatures are unseasonably warm in some areas off Southern California, but only by a couple of degrees. Temperatures are significantly warmer than usual, however, off parts of western Mexico, including the Sea of Cortez.

This not only drives fish populations and some mammals beyond their typical range, but it causes shifts in bait fish populations.

Sam Anderson, a UC Davis biologist and part of a survey team that visited traditional nesting sites, told ABC News that where they would typically encounter tens of thousands of breeding pairs of pelicans, there were only sparse numbers. Some nesting sites were alarmingly deserted.

“That’s what we call a failure, a bust. The bottom dropped out,” Anderson said.

Mark Rayor, who runs Jen-Wren Sportfishing in the Sea of Cortez, in Baja California’s East Cape region, said sardines and other types of bait fish are largely absent.

Rayor has logged water temperatures as high as 86 degrees, which is more typical of late July or August. He said blue marlin and sailfish, which generally begin to arrive in early August, are already showing in the offshore blue water. (Above NOAA chart shows where sea-surface temperatures are abnormally warm in portions of the Pacific.)

Anderson, however, was reluctant to place all of the blame for the pelicans’ plight on the developing El Niño.

“During most El Niño events we’ve seen, numbers of nesting attempts drop by at least half to two-thirds, and production goes down, too. But it drops from thousands to hundreds, not 10 or less.”

Whether El Niño is to blame or not, however, a powerful El Nino appears imminent, and the marine environment, on this side of the equator anyway, is already somewhat off-kilter.

And these are just some of the early messengers of change; they probably won’t be the last.

Yes, indeed El Nino looks likely and I think we start feeling the effects of this by September as well. It appears to be an east based El Nino and with a negative NAO could spell very heavy snows in the Mid Atlantic points northeastbound. Now a caveat to this will be the rapidly warming waters of the Gulf of Mexico and up and down the East Coast during the last two weeks or so. The waters here are also warming rapidly which would be fuel for large noreasters come this fall and winter!!